Introduction Cervical cancer is not the only cancer attributable to human papillomavirus (HPV). Of vaginal cancers around 78% and of vulvar cancers around 25% are caused by HPV. The number of these cancers is estimated to grow among younger women as HPV prevalence rises. The world population growth and aging will also increase the burden of these cancers. Our aim was to examine if HPV screening for cervical cancer could have an additional beneficial effect and prevent also vaginal and vulvar cancers. To assess this, we used a long-term follow-up data of the Finnish randomized HPV screening trial.

Methods Between 2003 and 2007, over 236 000 individuals were randomized (1:1) to HPV or to cytology screening in Southern Finland. The median follow-up time was 15 years. To compare the study arms, we calculated the incidence rate ratios for vaginal and vulvar cancers combined using Poisson regression. Analyses were performed with the intention to treat -principle.

Results During 3,5 million person-years of follow-up, we detected a total of 51 vaginal or vulvar cancers and 12 cancer deaths in the HPV arm, and 78 cancers and 18 cancer deaths in the cytology arm. The incidence rate ratio for vaginal and vulvar cancers was 0.67 (95% CI 0.47–0.94) in the HPV arm compared to cytology arm.

Conclusion/Implications Based on our results, HPV screening could prevent vaginal and vulvar cancers. The result is promising and suggests that the growing burden of vaginal and vulvar cancers could be reduced by HPV screening. Further research on the topic is needed.